# NAME

Math::Int2Base - Perl extension for converting decimal (base-10) integers into another number base from base-2 to base-62, and back to decimal.

# SYNOPSIS

```
use Math::Int2Base qw( int2base base2int base_chars );
my $base = 16; # i.e., hexidecimal
my $hex = int2base( 255, $base ); # FF
my $dec = base2int( $hex, $base ); # 255
my $sixdig = int2base( 100, 36, 6 ); # 00002S
my $decno = base2int( $sixdig, 36 ); # 100, i.e., leading zeros no problem
my $chars = base_chars( 24 ); # 0123...KLMN
my $regex = qr/^[$chars]$/; # used as character class
use bigint; # if needed
my $googol = 10**100;
my $base62 = int2base( $googol, 62 ); # QCyvrY2MJnQFGlUHTCA95Xz8AHOrLuoIO0fuPkHHCcyXy9ytM5N1lqsa
my $bigint = base2int( $base62, 62 ); # back to 1e+100
# from one base to another (via base-10)
sub base_convert {
my( $num, $from_base, $to_base ) = @_;
return int2base( base2int( $num, $from_base ), $to_base );
}
```

# DESCRIPTION

Math::Int2Base provides

`int2base( $int, $base, $minlen )`

for converting from decimal to another number base,`base2int( $num, $base )`

for converting from another base to decimal, and`base_chars( $base )`

for retrieving the string of characters used to represent digits in a number base.

This module only works with positive integers. Fractions are silently truncated to integers.

# CONSTRAINTS

Only (so far) supports bases from 2 to 62

Does not (yet) support bases that skip digits (e.g., base-24 skips

`I`

and`O`

, Math::Int2Base doesn't)Only supports positive integers.

Does not support flexible case letters, e.g., in hexidecimal,

`F`

==`f`

.In Math::Int2Base,

`f`

is not a hex digit, and`A`

(base-16) ==`A`

(base-36) ==`A`

(base-62).

# SEE ALSO

http://en.wikipedia.org/wiki/Category:Positional_numeral_systems Math::BaseCnv Math::BaseCalc

The code is based on newsgroup discussion http://groups.google.com/group/comp.lang.perl.misc/browse_thread/thread/3f3b416e3a79fd2/d2f62e10c837e782 particularly that of Dr. Ruud. Errors are my own.

# AUTHOR

Brad Baxter, <bbaxter@cpan.org>

# COPYRIGHT AND LICENSE

Copyright (C) 2010 by Brad Baxter

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.6 or, at your option, any later version of Perl 5 you may have available.